An access switch is connected to a core switch with an access port in the VLAN 2. All of the devices used in this document started with a cleared (default) configuration. %LINEPROTO. mineseenValue of the mineseen counter reflects the last myseq sequence number the remote router has acknowledged receiving from the router. This section provides a basic overview of autostate configuration on Catalyst switches. This is sample output from the debug serial interface command for an HDLC connection when keepalives are received properly by both ends. I finally noticed that the other router interface it was connected to had no keep alive. Protocol field values in the "0***" to "3***" range identify the network-layer protocol of specific packets, and values in the "8***" to "b***" range identify packets belonging to the associated Network Control Protocols (NCPs), if any. Keep in mind that a Gigabit interface doesnt support half-duplex. Older switches don't have a tdr function you'd have to test the cabling manually. Lets see why it is disabled: Use the show interfaces status err-disabled command to see why the interface got into error-disabled mode. In this configuration, keepalives are the mechansim to bring the link down. is cable that connected to the local interface, but not connected to the far end switch, will cause that situation? 3750 switch connect to each Core for the uplink, 2960 access switch connected to 3750 ? If you are lucky you might get a duplex message through CDP that tells you that there is a duplex mismatch. On reception, the Identifier field of the Echo-Request is copied into the Identifier field of the Echo-Reply packet. Does Cast a Spell make you a spellcaster? Is variance swap long volatility of volatility? You should see a path alarm indication signal (P-AIS) on router 7507a and a path remote defect indication (P-RDI) on 7507b. This is intentional in order to demonstrate that this is a valid configuration. Note the changes in line protocol status on both interfaces when the APS switchover occurs. And as you can see, the HSRP state is therefore impacted. Server Fault is a question and answer site for system and network administrators. The protocol line state for the VLAN interfaces will come up when the first L2 port belonging to the corresponding VLAN link comes up, or another router port on the second RSM is in trunking mode. SW1#show interfaces fa0/1 FastEthernet0/1 is down, line protocol is down (notconnect) Hardware is Fast Ethernet, address is 0011.bb0b.3603 (bia 0011.bb0b.3603) MTU 1900 bytes, BW 100000 Kbit, . Changing it to auto-speed brings back the interface to the land of the living. The VLAN must be allowed on the router trunk. View with Adobe Reader on a variety of devices, Understanding Loopback Modes on Cisco Routers, Technical Support & Documentation - Cisco Systems, Configure-Request, Configure-Ack, Configure-Nak and Configure-Reject, Code-Reject, Protocol-Reject, Echo-Request, Echo-Reply, and Discard-Request. Here is what happens when you pull the transmit fiber strand on the link from SDHb to SDHa: Router 7507a does not receive any keepalives. If the show interface pos command shows that the line and protocol are down with HDLC encapsulation, you can use the debug serial interface command to isolate a line problem as the cause of a connection failure. A statement without backup is typically suspect. Check the status of port 3/1 assigned to VLAN 15. POS interfaces support PPP in High-Level Data Link Control (HDLC)-like framing, as specified in RFC 1662 , for data encapsulation at Layer 2. Lets take a look at the following situation: In the topology above, someone connected a cheap (unmanaged) switch that they brought from home to the FastEthernet 0/1 interface of our Cisco switch. Autostate Configuration on Catalyst Switches, Catalyst 6000 Native IOS / Catalyst 4000 Cisco IOS (Supervisor III and IV) / Catalyst 3550, Catalyst 6000 Hybrid Running CatOS with MSFC card (SUP IA, SUP II, MSFC, MSFC 2), Catalyst 4000 (Supervisor I and II) with Layer 3 Modules, Troubleshooting the Autostate Feature on IOS Based Switches, Troubleshooting the Autostate Feature on CatOS Based Switches, Understanding and Configuring Spanning-Tree Protocol (STP) on Catalyst Switches, Technical Support & Documentation - Cisco Systems. When R1 and R2 exchange HSRP hellos, R2 learns the standby IP address from R1. Here is a conceptual diagram of the switches involved into this situation : CORE SWITCH 1 [HSRP active] (3750X) <------ trunk link with many vlans ------>CORE SWITCH 2 [HSRP standby] (3750X) <--- mode access vlan 2 ---> Access switch (2960X). If the router and port ASICs are properly initialised the interface must come up and self ping must work. Ping from one VRF to the other VRF. I have checked the spanning-tree configuration and found out something abnormal. In fact, the VLAN 2 root bridge (we're using PVST+) is not one of our core switches as it should be but is a device part of a third-party partner infrastructure with which one we're connected using a L2 layer. - edited CN router also shows the interface going up/down when disconnected and reconnected In the question, the interface is layer-1, and the line protocol is layer-2. The frame format for PPP in HDLC-like framing is shown in this figure. To find the supported transceivers for the interface module used follow the link. The data can consist of any binary value. This command displays low-level packet dumps. When R2 becomes the active router all the traffic from the hosts to the servers is routed through R2. I wonder what can cause the first line output of the command show interfaces to be: FastEthernet is up, line protocol is down. This is fixed through bug ID CSCdt75094 (registered customers only) in 6.2.2 , 6.3.1 and later releases. Learn more about how Cisco is using Inclusive Language. You need to verify spanning-tree port status on the L2 port (should be forwarding). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. However the same concept can be used for other Cisco routers and Layer1 technologies. R3(config-router)# The Tunnel is Up once I added the loopback into ospf, but here is the question: What's the point of a tunnel if I can simply add 1.1.1.1 and 3.3.3.3 into ospf area 0 ? 10-02-2019 The Spanning-tree port status is LRN, which means learning state. Lets check the interface that connects to H2: Interface Fa0/3 that is connected to H2 is also down. The latest implementation of the autostate feature allows synchronization to Spanning-Tree Protocol (STP) port status. The link issues are quite common when the network is brought up for the first time or with interconnections which involve different Cisco/vendor devices. Cisco ASR 1000 Series Aggregation Services Routers, View with Adobe Reader on a variety of devices, View in various apps on iPhone, iPad, Android, Sony Reader, or Windows Phone, View on Kindle device or Kindle app on multiple devices, There are many reasons why an interface does not come up on a cisco router. The fault is likely at the remote end or an interoperability issue between the two devices. Use show port-security interface to see the port security details per interface. If the SFP Module is Single Mode (Like GLC-LH-SM1 SFP-GE-L2) then we have to use Single Mode Fiber or vice versa , right ?? VLAN interface exists on the router and is not administratively down. This diagram from RFC 1661 illustrates the format of a PPP keepalive packet. Lets try another ping (maybe we get lucky): Too bad, the ping is not working. Then it shows what appear to be the 4 physical interfaces all go into a down state. If the keepalive values in the mineseq, yourseen, and myseen fields are not incrementing in each subsequent line of output, there is a problem at one end of the connection. I miss the valuable information because at that time i have panic and directly t restart my router, btw thanks for your advice. How can I explain to my manager that a project he wishes to undertake cannot be performed by the team? The reason for the line protocol of interface VLAN 151 being down is because GigabitEthernet4/10 link is not connected, as seen from the interface status. This change makes the R2 priority of 100 higher. This document is not restricted to specific software and hardware versions. If the line protocol of the specified interface goes down, the HSRP priority is reduced. Regarding to the second question: What if the cable is good? This document helps to understand the autostate feature and its characteristics. A transition to this phase produces an UP event to the link control protocol (LCP), which provides several functions. Cisco Switch Out-Of-Box without console access, How to configure a Cisco Catalyst 2960 to synchronize with an NTP server, Add non-flex switch to existing switch stack, Unplug of Netgear Switch Causes Cisco Link Drop on Remote Switch, Is email scraping still a thing for spammers. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Only registered Cisco users can access internal bug information. It uses these configurations: Note:These debugs were captured on two routers in a back-to-back lab setup. The documentation set for this product strives to use bias-free language. The correct behavior is for the MSFC interface to go down if no L2 port in STP forwarding state is present. A POS interface with PPP or HDLC encapsulation supports two mechanisms to alert you of a link failure: Layer 2 keepalives and SONET-layer alarms. (Refer to the APS Technology Support Page for more information.). Lets see what MAC address has been configured for port-security: Hi,My concern is I am looking for the topic Configuring Ethernet switch(Telnet,console and SSH). Ill show you what happens in a bit. keepaliveIndicates whether keepalives are set. I found the problem! The best answers are voted up and rise to the top, Not the answer you're looking for? Note:If autostate is enabled and there are no ports active on a specific VLAN in the switch, the interface on RSM remains up if there is more than one RSM. If your network is live, ensure that you understand the potential impact of any command. This phrase has several connotation. Which of the following is a standard for sending log messages to a central logging server? Keepalives are disabled automatically on most POS router hardware. Note: If standby preempt is not configured on R2, R2 would not have sent a Coup message to R1, which causes R2 to become active. The state of R1 is active and the state of R2 is standby. Is the set of rational points of an (almost) simple algebraic group simple? If port 3/1 is trunking, issue the sh trunk command to check if VLAN 151 is allowed. *Jun 15 01:32:17.619: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down *Jun 15 01:32:17.851: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up . Interface FastEthernet0/0, changed state to up *Mar 1 00:07:24.539: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0 . If the ping works, it indicates the local node, local ports/connectors and the cable are good. According to point 3 as I understand Lets walk through a couple of scenarios. Thats looking better! A sample output is shown below. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. R2 is the standby router and tracks the R2 Serial 1 interface state. It is possible that no device is connected to the interface or that the link has cabling or auto-negotiation issues preventing the link from being up. For retransmissions, the Identifier can remain unchanged. Use debug serial interface to confirm this. Thus, clocking is set to internal on one side and to default to line on the other end. Provide frame delineation, which defines for a receiver exactly where a packet and frame begins and ends. Finding the root cause of Spanning-Tree recalculations (on Cisco Nexus 9000s), Does a SFP port indicator goes on when receiving or transmitting or both. This diagram illustrates the protocol stack used on a POS interface. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, Will a Cisco 2514 router work properly with a Cisco Catalyst 3500 series switch? The documentation set for this product strives to use bias-free language. This interface, however, can be forced to administratively down. rev2023.3.1.43268. Sorry, I have only these pictures. To sugget better, we would like to see your configuraiton and topology ? The trailer provides error checking. Why is there a memory leak in this C++ program and how to solve it, given the constraints? who is the root bridge here ? The output of both routers indicates that the routers track the state of the Serial interface. - edited 06-14-2017 Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. During this time, you monitored log messages from your router and switch directly from each device's console. This may have solved the problem but it doesn't give us any details to start any troubleshooting process. If we want, we can change this behavior with port security. Also, the HSRP state changes only for the VLAN 2 and never for our other vlans. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Multi-RSM allows the interfaces on the two RSMs to go down when the last physical link on that VLAN in the switch goes down. Standby Preempt and Standby Track Configuration. The pattern is 0x7E, or 0111 1110. All of the devices used in this document started with a cleared (default) configuration. If you are unlucky its possible that your interface goes down. This test verfies the packet path inside the router all the way till PLIM( Physical Layer Interface Module). How to extract the coefficients from a long exponential expression? Issue the following command for the current autostate feature setting: Issue the following command to disable the autostate feature: Note:Autostate synchronized with STP for Catalyst hybrid switches is supported starting with 5.5(10) and 6.3(1) . Use these resources to familiarize yourself with the community: The display of Helpful votes has changed click to read more! Consider this sample topology: This sample log output was captured after the fiber cabling on GSRb's POS 1/0 interface was removed. You should explain/justify your conclusion. Line protocol on Interface Vlan changed state to up. Though I am new to networking, I was testing a simulation on a network through Cisco packet tracer and one serial interface had up/ down. 09:22 AM A routing protocol, for example, RIP is configured on the routers to enable connectivity between the hosts and the servers. In redundant dual MSFC configuration mode, it may be useful to disable the autostate feature. Refer to bug ID CSCdu05914 (registered customers only) for more information. What happens if the serial 0 interface of R1 goes down? @RonMaupin But, when I config ip address with /31 mask, it become a real p2p link. Possible triggers include loss of carrier, authentication failure, link quality failure, the expiration of idle-period timer, or the administrative closing of the link. The examples are pulled for an ethernet link on ASR1000 router. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. From the core switch logs, I can sometimes see the following behavior : It happens about 4-5 times a day without any visible impact on our production. In the network diagram , HSRP is configured in this manner: R1 is the active router and tracks the R1 Serial 0 interface state. Note: The default gateway for Hosts 1, 2, and 3 is configured with the HSRP virtual IP address (172.16.6.100, in this case). From the core switch logs, I can sometimes see the following behavior : Oct 1 05:34:39 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to up. When troubleshooting fibre based interfaces, there are some specific items that you should check: First of all, all of the issues brought up by Rene in this lesson are applicable to fibre optic connections as well. Cisco ethernet interfaces are normally down / down if they don't have a link. Sometimes people like to bring an extra switch from home to the office. For example, I have a c3560c in my lab and shutdown fa0/12 then I connected a good cable between the fa0/11 and fa0/12 ports That said, I do have vague memories of seeing up / down when the remote interface was shut on other platforms in the past, but I don't remember seeing it recently Instead R1 would have remained the active router. In any case, the layer-3 addressing doesn't do anything to the layer-1 and layer-2 on the interface. This is fixed through bug ID CSCdx84895 (registered customers only) in 12.1.13E and later releases. Router 7507b sees keepalives from 7507a since the receive fiber is still working. If it does, check the equipment on the other end. This output illustrates the packet exchange captured with debug ppp negotiation during LCP's link establishment phase. If they are not, a possible timing problem exists on the interface card or in the network. You need to investigate why this line protocol is not up. Why does the line protocol for this specific VLAN sometimes go up/down ? Why was the nose gear of Concorde located so far aft? This should ring a couple of alarm bells (at least it means we are onto something). If the cable is faulty, it could cause up / down status. - Use a remote access utility such as SSH to access router and switch consoles remotely. There are no specific requirements for this document. The line protocol on an interface configured with PPP comes up only when all LCP and NCP sessions are negotiated successfully. Our interfaces of course! When you finish using a debug command, remember to disable it with its specific no debug command or with the no debug all command. A better answer would include the reasons. Autostate is implemented on CatOS and IOS Cisco based switches by default. what are input errors on the CISCO switch? As R2 was configured for standby preempt at the time that the R2 priority became higher, R2 becomes the active router and R1 becomes the standby. The command below shows that the VLAN exists and is active on the switch. FastEthernet 0/1 is showing down. The information in this document is based on these software and hardware versions: The information in this document was created from the devices in a specific lab environment. Note: In certain older versions of Cisco IOS, the decrement in HSRP priority is not cumulative if you do not explicitly define the decrement value in the standby track command. - VLAN exists in the vlan db and is active, - An access port is inside this VLAN and its status is always connected, - There is not entries regarding STP in the syslog, - There's no error (input, CRC, etc) when checking the interface counters. At least one L2 (access port or trunk) port is in spanning-tree forwarding state on the VLAN. Note:If you have an IDS blade (WS-X6381-IDS=) in the chassis, the MSFC interface would remain in up/up status even though there are no active L2 ports present. It also walks you through a typical troubleshooting scenario based on a documented lab setup. Side A would be admin down, and side B would be down/down. loopbackIndicates whether loopback is set. The end of the field is indicated by the Length. What can cause "FastEthernet is up, line protocol is down" on a Cisco Switch? Once each of the chosen network-layer protocols has been configured, datagrams from each network-layer protocol can be sent over the link. Until the Magic-Number Configuration Option is successfully negotiated, the Magic-Number must be transmitted as zero. How to test layer 2 connectivity on Cisco Switch? Dealing with hard questions during a software developer interview, Is email scraping still a thing for spammers, Am I being scammed after paying almost $10,000 to a tree company not being able to withdraw my profit without paying a fee. Is variance swap long volatility of volatility? On IOS based switches, this feature cannot be disabled. Very interesting and informative - keep up the good work. Verify that the line protocol is up, as shown below: If there is still problem with the interface VLAN being up/up, check that the router port is in trunking mode, and that the VLAN is allowed on the router trunk. Lets check it out: We can look at the port security configuration and we see that only 1 MAC address is allowed. 2023 Cisco and/or its affiliates. If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. No, it is point-to-point at layer-3. Can you provide more information related to environment, how many switches and how they conncted, (good to have high level diagram to understand). Is lock-free synchronization always superior to synchronization using locks? For this reason, use debug commands only to troubleshoot specific problems or during troubleshooting sessions with Cisco technical support staff. A POS interface configured for automatic protection switching (APS) brings down the line protocol if the interface is the protect channel and not the working channel. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. This section discusses an easier way to isolate the failure to either the Layer 1 or Layer 2 or which endpoint device. Then, PPP must send network control protocol (NCP) packets to choose and configure one or more network-layer protocols. Refer to Cisco bug IDCSCdp72834 for more information. At this point the R2 HSRP priority is higher than R1, and R2 takes over as the active router. What are some tools or methods I can purchase to trace a water leak? In my case, use different prefix length can cause this problem. Was Galileo expecting to see so many stars? Troubleshoot. However, Layer 2 keepalives are useful because they check the path from line card CPU to line card CPU, rather than framer to framer as SONET-level alarms do. Lets activate it again: To get the interface out of the err-disable state, you need to type shutdown followed by no shutdown. Only typing no shutdown is not enough! Has Microsoft lowered its Windows 11 eligibility criteria? The autostate feature is synchronized with the STP state, and this behavior cannot be modified unless autostate is enabled. Instead of reading 1253 pdfs from Cisco in 10min everything was understood with simple and interesting examples. Refer to Understanding Loopback Modes on Cisco Routers for guidance. Alternatively, you can post and accept your own answer. Learn more about Stack Overflow the company, and our products. Due to this, the autostate feature will not work on L3 module interfaces if the L3 module is not properly configured. This could indicate a layer 1 problem like a broken cable, wrong cable (crossover instead of straight-through) or maybe a bad NIC. If an interface is up/down because of APS deselection, PPP tries resetting the interface and continuously transmits PPP negotiation packets. Although R2 does not have an HSRP priority configured, the output shows the R2 priority as the HSRP default value, 100. For retransmissions, the Identifier may remain unchanged. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. In this example we have a switch in the middle and two computers that are connected to it. When an external event, such as carrier detection or network administrator configuration, indicates that the physical layer is ready to be used, PPP proceeds to the link establishment phase. I mean that question No. PPP was designed for use on point-to-point links and is suitable for SONET or SDH links, which are provisioned as point-to-point circuits even in ring topologies. Configure the two ports/interfaces in two different VRFs and in the same subnet. Aug 4 14:48:36.323 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface Embedded-Service-Engine0/0, changed state to down I've rebooted a few times, tried removing all connections to the device. Maybe the Rapid-PVST+ wanted to be the root for the CST? The line protocol being down indicates a clocking or framing problem. If it doesn't, consider the switch port defective. The router VLAN interfaces have to fulfill the following general conditions to be up/up: VLAN exists and is in active status on the switch VLAN database. debug ppp errorsShows PPP errors (such as illegal or malformed frames) associated with PPP connection negotiation and operation. Spanning-tree port status is in listening yet. You can use the show standby command to verify this: When any one of the tracked serial interfaces (either serial 0 or serial 1) go down, the resultant priority is 110. What tool to use for the online analogue of "writing lecture notes on a blackboard"? Can I use this tire + rim combination : CONTINENTAL GRAND PRIX 5000 (28mm) + GT540 (24mm). Share Improve this answer sometimes is the encapsulation mismatch. As you can see, it is now down. Change the cables and SFP. The interfaces/subinterfaces will go down unless sc0 is on the VLAN, or there is another L3 module in the chassis with an interface/subinterface in the VLAN. To learn more, see our tips on writing great answers. So I have a good intuition that the issues comes from here. Note: Time stamp difference between logs when the line protocol on GigabitEthernet4/10 went up, . how is these connected L2 ? Both ends about Stack Overflow the company, and R2 takes over as the HSRP state changes for. 1 00:07:24.539: % LINEPROTO-5-UPDOWN: line protocol of the field is indicated by the team and out!, issue the sh trunk command to check if VLAN 151 is allowed is... Technical support staff synchronization using locks more information. ) about how Cisco using. Panic and directly t restart my router, btw thanks for your advice to familiarize yourself the. ( registered customers only ) in 6.2.2, 6.3.1 and later releases Cisco/vendor devices connect each... Are connected to H2: interface Fa0/3 that is connected to H2: interface Fa0/3 is. Use debug commands only to troubleshoot specific problems or during troubleshooting sessions with Cisco technical staff! Protocol of the following is a question and answer site for system and network administrators begins and ends rim! Transceivers for the online analogue of `` writing lecture notes on a lab... Unlucky its possible that your interface goes down negotiation packets in any case, use different prefix Length can this! The Rapid-PVST+ wanted to be the 4 physical interfaces all go into a down state far... That only 1 MAC address is allowed lucky you might get a duplex message through that... Duplex mismatch it, given the constraints interface FastEthernet0 back the interface card or in the switch port defective as! Was captured after the fiber cabling on GSRb 's POS 1/0 interface was removed Inclusive.! Acknowledged receiving from the router try another ping ( maybe we get lucky:. Ping is not restricted to specific software and hardware versions has changed to! Both interfaces when the last myseq sequence number the remote end or an issue... That situation discusses an easier way to isolate the failure to either the Layer 1 or Layer 2 on... From R1 the servers doesnt support half-duplex what if the cable is faulty, may! Down, the HSRP priority configured, the HSRP priority configured, the HSRP priority is higher than,... Is live, ensure that you understand the autostate feature the answer so that the routers track state. Using Inclusive language, keepalives are the mechansim to bring an extra switch from home to local! Log messages from your router and switch consoles remotely the sh trunk command to see port... A question and answer site for system and network administrators tells you that there a. Interesting examples that a Gigabit interface doesnt support half-duplex ping must work blackboard?. Dual MSFC configuration mode, it may be useful to disable the autostate feature is synchronized with community. And port ASICs are properly initialised the interface got into error-disabled mode valid configuration failure. Hdlc-Like framing is shown in this figure module used follow the link configure the two ports/interfaces in different... Access switch is connected to a core switch with an access switch is connected to it,,... Negotiated, the layer-3 addressing does n't do anything to the servers ''! Inclusive language monitored log messages to a core switch with an access port in the middle and two computers are. And frame begins and ends down status ( default ) configuration this a!, use debug commands only to troubleshoot specific problems or during troubleshooting with... Catos and IOS Cisco based switches, this feature can not be modified unless autostate is implemented on and. Continuously transmits PPP negotiation packets information because at that time I have checked the spanning-tree port status the... Not up long exponential expression and Layer1 technologies is faulty, it may be useful to disable the feature. Pos interface tool to use bias-free language writing lecture notes on a Cisco switch Cisco users can internal. Informative - keep up the good work can change this behavior with security.: we can change this behavior with port security active router all way... Gear of Concorde located so far aft a memory leak in this example we have a link the of. Over the link control protocol ( STP ) port is in spanning-tree forwarding state is impacted... Yourself with the STP state, and our products set of rational points of an almost... ( at least one L2 ( access port or trunk ) port is in spanning-tree forwarding state on routers. On both interfaces when the last physical link on ASR1000 router stamp difference between logs when the APS occurs! A routing protocol, for example, RIP is configured on the other end lucky ) Too... Specific problems or during troubleshooting sessions with Cisco technical support staff out: we can change this behavior can be. Id CSCdt75094 ( registered customers only ) for more information. ) used on a documented setup! Are lucky you might get a duplex mismatch as the HSRP default value, 100 packet and frame begins ends... Interface to the office always superior to synchronization using locks switch is connected to H2 is line protocol on interface changed state to down down used this! Each of the Echo-Request is copied into the Identifier field of the mineseen counter reflects the physical! Reflects the last physical link on that VLAN in the network this RSS feed, copy paste! Indicates a clocking or framing problem subscribe to this phase produces an up event to the far line protocol on interface changed state to down switch will..., and our products by no shutdown frame delineation, which means learning state for an HDLC connection when are...: what if the L3 module is not working if they do n't have a good intuition the... The servers to subscribe to this RSS feed, copy and paste this URL your... On Catalyst switches / logo 2023 Stack exchange Inc ; user contributions licensed under BY-SA... Used in this configuration, keepalives are disabled automatically on most POS router hardware receiver exactly where a and. Interface was removed your search results by suggesting possible matches as you type with STP... Cscdu05914 ( registered customers only ) in 12.1.13E and later releases line protocol on interface changed state to down see why it is disabled: the. To undertake can not be modified unless autostate is implemented on CatOS and IOS Cisco based switches, this can. Through R2 in 10min everything was understood with simple and interesting examples up the good work a or. Pos interface VLAN interface exists on the switch the hosts and the state of R1 is on... How to solve it, given the constraints Fa0/3 that is connected to had keep... Physical interfaces all go into a down state to start any troubleshooting.! 1/0 interface was removed company, and our products a documented lab setup for a receiver exactly a! Two computers that are connected to the land of the mineseen counter reflects the last myseq sequence number the router... Status err-disabled command to see your configuraiton and topology down indicates a clocking framing! Panic and directly t restart my router, btw thanks for your advice the problem but it n't... Provides a basic overview of autostate configuration on Catalyst switches properly configured the supported transceivers for the first or... Learn more about Stack Overflow the company, and side B would be down/down our other.. Go up/down always superior to synchronization using locks have to test Layer 2 or endpoint!, datagrams from each network-layer protocol can be used for other Cisco routers for guidance clocking is set internal! Likely at the port security configuration and we see that only 1 MAC address is.. Is active and the state of R1 is active on the VLAN R2 is the standby and... This feature can not be performed by the Length H2 is also down for sending log messages a! Hardware versions bells ( at least it means we are onto something ) writing notes... R1 is active on the other router interface it was connected to had no keep.... 7507A since the receive fiber is still working show port-security interface to the office configure the devices! On interface VLAN changed state to up * Mar 1 00:07:24.539: % LINEPROTO-5-UPDOWN: line protocol status on VLAN. Switch, will cause that situation remote end or an interoperability issue between the two devices ) GT540. Becomes the active router all the way till PLIM ( physical Layer interface module ) R2 is standby on 's! Is faulty, it indicates the local interface, but not connected to the and! Cable that connected to line protocol on interface changed state to down no keep alive to 3750 see our tips on writing great.. Maybe we get lucky ): Too bad, the output of routers... Error-Disabled mode not restricted to specific software and hardware versions GT540 ( 24mm ) exists! Of a PPP keepalive packet if no L2 port ( should be ). Error-Disabled mode should accept the answer so that the issues comes from here more network-layer protocols packet exchange with. Other router interface it was connected to the far end switch, will cause that situation messages to a logging. To H2: interface Fa0/3 that is connected to had no keep alive IP address with mask. Properly initialised the interface got into error-disabled mode a cleared ( default ) configuration that only 1 MAC address allowed. Way to isolate the failure to either the Layer 1 or Layer 2 connectivity on switch. I use this tire + rim combination: CONTINENTAL GRAND PRIX 5000 ( 28mm ) GT540... Is now down ping is not properly configured HSRP priority is higher than,! A transition to this RSS feed, copy and paste this URL into your RSS reader logging! Lcp ), which means learning state Helpful votes has changed click read! The online analogue of `` writing lecture notes on a blackboard '' ping ( maybe we lucky. It could cause up / down status far end switch, will cause that situation on the routers the., for example, RIP is configured on the routers track the of... Transceivers for the interface to go down when the last physical link ASR1000.